1. Field of the Invention
The present invention relates to a fuel injection apparatus in which fuel within a fuel tank is boosted by a fuel pump, and the boosted fuel is injected and supplied to an engine via a fuel injection valve, and more particularly to an air bypass apparatus supplying controlled idle air into an intake passage at a downstream side of a throttle valve while bypassing the throttle valve, at a time of an idling operation of the engine and at a time of an off-idle operation.
2. Description of the Conventional Art
A conventional air bypass apparatus is disclosed in PCT/JP2005/006560 and Japanese Patent Application No. 2005-324824, a whole structure of the air bypass apparatus is disclosed in PCT/JP2005/006560, and a locking structure between a slider and an air control valve is disclosed in Japanese Patent Application No. 2005-32482.
A structure of an air bypass apparatus arranged on the basis of PCT/JP2005/006560 is disclosed in FIG. 8, and will be explained by this drawing.
Reference numeral 10 denotes an air control valve main body in which a motor insertion hole 11 and a valve body guide hole 12 are continuously provided from an upper end surface 10a toward a lower side. An air control hole 13 is open to a side wall 12a of the valve guide hole 12, and a downstream side of the air control hole 13 is open so as to communicate with an inner side of an intake passage 15 passing through a throttle body 14 and an inner side of an intake passage 15a at a downstream side of a throttle valve 16. On the other hand, an air inflow hole 17 is open to a portion near a bottom portion 12b of the valve body guide hole 12, and an upstream side of the air inflow hole 17 is open so as to communicate with an inner side of an intake passage 15b at an upstream side of the throttle valve 16. (In the description mentioned above, the upstream side and the downstream side are called in an air flow direction.)
In this case, the intake passage 15b at the upstream side communicate with an air cleaner (not shown) by an air pipe, the intake passage 15a at the downstream side communicate with an engine (not shown) by an intake pipe, and a fuel controlled by a fuel injection valve (not shown) is injected and supplied into the intake passage 15 or the intake pipe.
Reference symbol M denotes a motor such as a step motor or the like in which an output shaft Ma protrudes toward a lower side. A motor case Mb formed by a synthetic resin material is out molded in an outer periphery of the motor M, and a tube portion Mc surrounding the output shaft Ma is formed in the motor case Mb so as to be open toward a lower side. Reference numeral 17 denotes a rotation suppressing member formed in a tubular shape. A rotation suppressing groove 17b is provided in an inner peripheral wall 17a thereof in a vertical direction in the drawing, and the rotation suppressing member 17 is inserted into the tube portion Mc from a lower opening of the tube portion Mc so as to be fixed. For example, it is light pressure inserted.
In accordance with the structure mentioned above, the rotation suppressing member 17 is fixedly arranged in an inner side of the tube portion Mc of the motor case Mb provided with the motor M, and the output shaft Ma is arranged in an inner side of the inner peripheral wall 17a of the rotation suppressing member 17. The motor case Mb is structured such that a U-shaped groove of a tabular attaching member 18 is fitted to an inner side of an annular groove Md provided in an outer periphery of the tube portion Mc as well as a lower side of the tube portion Mc is inserted into the motor insertion hole 11 of the air control valve main body 10, and the attaching member 18 is fixed by screw to the air control valve main body 10 via a screw 19 as well as being arranged on an upper end surface 10a of the air control valve main body 10 in a contact manner.
Reference numeral 20 denotes a slider screwed to a male thread formed on an outer periphery of the output shaft Ma. The slider 20 is formed by an annular collar portion 20a and a shaft portion 20b protruding toward a lower side from the annular collar portion 20a, and a protruding portion 20c inserted into the rotation suppressing groove 17b of the rotation suppressing member 17 is integrally formed at a part of an outer periphery of the annular collar portion 20a so as to protrude sideward.
In accordance with the structure mentioned above, when the output shaft Ma is rotated in synchronization with the motor M, the rotation of the slider 20 is suppressed by the protruding portion 20c and the rotation suppressing groove 17b, whereby the slider 20 is moved up and down in the drawing in correspondence to the rotating direction of the motor M.
Reference numeral 21 denotes an air control valve arranged within the valve body guide hole 12 so as to be movable in a vertical direction, and is formed in a closed-end tubular shape in which a tube portion 21b is integrally formed from a bottom portion 21a toward an upper side.
The air control valve 21 mentioned above is arranged so as to face to an outer periphery 20d of the shaft portion 20b of the slider 20, and a bottom portion 21a thereof is arranged on an E clip 22 fixedly arranged so as to be fitted to a lower end of the shaft portion 20b of the slider 20 in such a manner as to be brought into contact by a spring 23. In other words, a contracted spring 23 is arranged in a space portion 25 formed between an inner side of the tube portion 21b and the outer periphery 20d of the shaft portion 20b, one end 23a of the spring 23 is locked to a lower surface of the annular collar portion 20a of the slider 20, and the other end 23b is locked to the bottom portion 21a of the air control valve 21. Accordingly, the bottom portion 21a of the air control valve 21 is elastically held so as to be pressed toward the E clip 22.
In accordance with the air bypass apparatus structured as mentioned above, when the motor M including the output shaft Ma is rotated in one direction, the rotation of the slider 20 is suppressed by the rotation suppressing groove 17b and the protruding portion 20c, thereby being moved, for example, in a downward direction in the drawing. Further, since the air control valve 21 is also synchronously moved in the downward direction on the basis of the downward movement of the slider 20, it is possible to control an opening area of the air control hole 13 in a reducing direction by the air control valve 21, and it is possible to regulate and control an amount of idle air supplied to the intake passage 15a at the downstream side in the reducing direction.
Further, when the motor M including the output shaft Ma is rotated in the other direction, the slider 20 is moved in an upward direction in the drawing.
Further, since the air control valve 21 is also synchronously moved in the upward direction on the basis of the upward movement of the slider 20, it is possible to control the opening area of the air control hole 13 in an increasing direction by the air control valve 21, and it is possible to regulate and control the amount of the idle air supplied to the intake passage 15a at the downstream side in the increasing direction, whereby it is possible to supply a desired amount of the idle air toward the engine.